Question

What is the difference between secondary active transport and active transport? Also what does it mean by something needs to move against its concentration gradient or along their concentration gradient?

Answer 1

Answere : The active transport of molecules can be of two types -

1. Primary active transport - This type of transport require energy for transport of molecules against the concentration gradient through breakdown of ATP. This type of transport require one binding site of AtP at cytosolic side.

2. Secondary active transport : This type of active transport require energy derived secondarily from energy that stored in the form of ionic differance i.e. electrochemical gradient across the membrane.

Meaning of "Somethimg moved against the concentration gradient" - It means that the molecules are moved from ita lower concentration to higher concentration across the membrane.

The meaning is reverse in case of along the concentration gradient.